Refactor models into models, fields and mixins

cms/__init__.py

@@ -1,2 +1,2 @@
-__version__ = '1.0.4'
-default_app_config = 'cms.apps.CmsConfig'
+__version__ = "1.0.5"
+default_app_config = "cms.apps.CmsConfig"

cms/fields.py

@@ -0,0 +1,74 @@
+from django.db import models
+from django.forms import TextInput
+
+from .mixins import EasilyMigratable
+
+
+class CharField(EasilyMigratable, models.TextField):
+    """Variable width CharField."""
+
+    def formfield(self, **kwargs):
+        if not self.choices:
+            kwargs.update({"widget": TextInput})
+        return super().formfield(**kwargs)
+
+
+class TextField(EasilyMigratable, models.TextField):
+    pass
+
+
+class SlugField(EasilyMigratable, models.SlugField):
+    pass
+
+
+class EmailField(EasilyMigratable, models.EmailField):
+    pass
+
+
+class BooleanField(EasilyMigratable, models.BooleanField):
+    pass
+
+
+class DateField(EasilyMigratable, models.DateField):
+    pass
+
+
+class DateTimeField(EasilyMigratable, models.DateTimeField):
+    pass
+
+
+class PositiveIntegerField(EasilyMigratable, models.PositiveIntegerField):
+    pass
+
+
+class DecimalField(EasilyMigratable, models.DecimalField):
+    pass
+
+
+class JSONField(EasilyMigratable, models.JSONField):
+    pass
+
+
+class FileField(EasilyMigratable, models.FileField):
+    pass
+
+
+class ImageField(EasilyMigratable, models.ImageField):
+    pass
+
+
+class ForeignKey(EasilyMigratable, models.ForeignKey):
+    def __init__(self, *args, related_name="+", **kwargs):
+        super().__init__(
+            *args,
+            related_name=related_name,
+            **kwargs,
+        )
+
+
+class ManyToManyField(EasilyMigratable, models.ManyToManyField):
+    pass
+
+
+class OneToOneField(EasilyMigratable, models.OneToOneField):
+    pass

cms/mixins.py

@@ -0,0 +1,74 @@
+class EasilyMigratable:
+    """
+    Mixin for model fields. Prevents the generation of migrations that
+    don't affect the database.
+    """
+
+    def deconstruct(self):
+        name, path, args, kwargs = super().deconstruct()
+        for field in [
+            "blank",
+            "choices",
+            "editable",
+            "help_text",
+            "limit_choices_to",
+            "related_name",
+            "storage",
+            "upload_to",
+            "validators",
+            "verbose_name",
+        ]:
+            if field in kwargs:
+                del kwargs[field]
+        return name, path, args, kwargs
+
+
+class Numbered:
+    """
+    Mixin for numbered models. Overrides the save() method to
+    automatically renumber all instances returned by
+    number_with_respect_to()
+    """
+
+    def number_with_respect_to(self):
+        return self.__class__.objects.all()
+
+    def get_field_name(self):
+        return self.__class__._meta.ordering[-1].lstrip("-")
+
+    def _renumber(self):
+        """Renumbers the queryset while preserving the instance's number"""
+
+        queryset = self.number_with_respect_to()
+        field_name = self.get_field_name()
+        this_nr = getattr(self, field_name)
+        if this_nr is None:
+            this_nr = len(queryset) + 1
+
+        # The algorithm: loop over the queryset and set each object's
+        # number to the counter. When an object's number equals the
+        # number of this instance, set this instance's number to the
+        # counter, increment the counter by 1, and finish the loop
+        counter = 1
+        inserted = False
+        for other in queryset.exclude(pk=self.pk):
+            other_nr = getattr(other, field_name)
+            if counter >= this_nr and not inserted:
+                setattr(self, field_name, counter)
+                inserted = True
+                counter += 1
+            if other_nr != counter:
+                setattr(other, field_name, counter)
+                super(Numbered, other).save()
+            counter += 1
+        if not inserted:
+            setattr(self, field_name, counter)
+
+    def save(self, *args, **kwargs):
+        self._renumber()
+        super().save(*args, **kwargs)
+
+    def delete(self, *args, **kwargs):
+        setattr(self, self.get_field_name(), 9999)  # hack
+        self._renumber()
+        super().delete(*args, **kwargs)

cms/models.py

@@ -1,117 +1,76 @@
 from django.db import models
 from django.urls import reverse
 from django.utils.text import slugify
-from django.forms import TextInput, Select
 from django.utils.translation import gettext_lazy as _
-from django.core.exceptions import ImproperlyConfigured
-
 from embed_video.fields import EmbedVideoField
 
-class VarCharField(models.TextField):
-    '''Variable width CharField'''
-    def formfield(self, **kwargs):
-        kwargs.update({'widget': TextInput})
-        return super().formfield(**kwargs)
+from . import fields, mixins
 
-class Numbered:
-    '''Mixin for numbered models. Overrides the save() method to
-    automatically renumber all instances returned by
-    number_with_respect_to()
 
-    '''
-    def number_with_respect_to(self):
-        return self.__class__.objects.all()
+class Model(models.Model):
+    """Felt cute, might delete later."""
 
-    def get_field_name(self):
-        return self.__class__._meta.ordering[-1].lstrip('-')
+    class Meta:
+        abstract = True
 
-    def _renumber(self):
-        '''Renumbers the queryset while preserving the instance's number'''
 
-        queryset = self.number_with_respect_to()
-        field_name = self.get_field_name()
-        this_nr = getattr(self, field_name)
-        if this_nr is None:
-            this_nr = len(queryset) + 1
+class BasePage(mixins.Numbered, Model):
+    """Abstract base model for pages."""
 
-        # The algorithm: loop over the queryset and set each object's
-        # number to the counter. When an object's number equals the
-        # number of this instance, set this instance's number to the
-        # counter, increment the counter by 1, and finish the loop
-        counter = 1
-        inserted = False
-        for other in queryset.exclude(pk=self.pk):
-            other_nr = getattr(other, field_name)
-            if counter >= this_nr and not inserted:
-                setattr(self, field_name, counter)
-                inserted = True
-                counter += 1
-            if other_nr != counter:
-                setattr(other, field_name, counter)
-                super(Numbered, other).save()
-            counter += 1
-        if not inserted:
-            setattr(self, field_name, counter)
-
-    def save(self, *args, **kwargs):
-        self._renumber()
-        super().save(*args, **kwargs)
-
-    def delete(self, *args, **kwargs):
-        setattr(self, self.get_field_name(), 9999) # hack
-        self._renumber()
-        super().delete(*args, **kwargs)
-
-class BasePage(Numbered, models.Model):
-    '''Abstract base model for pages'''
-    title = VarCharField(_('page'))
-    slug = models.SlugField(_('slug'), blank=True, unique=True)
-    number = models.PositiveIntegerField(_('number'), blank=True)
-    menu = models.BooleanField(_('visible in menu'), default=True)
+    title = fields.CharField(_("page"))
+    slug = fields.SlugField(_("slug"), blank=True, unique=True)
+    number = fields.PositiveIntegerField(_("number"), blank=True)
+    menu = fields.BooleanField(_("visible in menu"), default=True)
 
     def __str__(self):
         if not self.pk:
-            return str(_('New page'))
+            return str(_("New page"))
         return self.title
 
     def get_absolute_url(self):
         if self.slug:
-            return reverse('cms:page', args=[self.slug])
-        return reverse('cms:page')
+            return reverse("cms:page", args=[self.slug])
+        return reverse("cms:page")
 
     class Meta:
         abstract = True
-        verbose_name = _('Page')
-        verbose_name_plural = _('Pages')
-        ordering = ['number']
+        verbose_name = _("page")
+        verbose_name_plural = _("pages")
+        ordering = ["number"]
+
+
+class BaseSection(mixins.Numbered, Model):
+    """Abstract base model for sections"""
 
-class BaseSection(Numbered, models.Model):
-    '''Abstract base model for sections'''
     TYPES = []
-    title = VarCharField(_('section'))
-    type = VarCharField(_('type'))
-    number = models.PositiveIntegerField(_('number'), blank=True)
-    content = models.TextField(_('content'), blank=True)
-    image = models.ImageField(_('image'), blank=True)
-    video = EmbedVideoField(_('video'), blank=True, help_text=_('Paste a YouTube, Vimeo, or SoundCloud link'))
-    href = VarCharField(_('link'), blank=True)
+    title = fields.CharField(_("section"))
+    type = fields.CharField(_("type"))
+    number = fields.PositiveIntegerField(_("number"), blank=True)
+    content = fields.TextField(_("content"), blank=True)
+    image = fields.ImageField(_("image"), blank=True)
+    video = EmbedVideoField(
+        _("video"),
+        blank=True,
+        help_text=_("Paste a YouTube, Vimeo, or SoundCloud link"),
+    )
+    href = fields.CharField(_("link"), blank=True)
 
     def number_with_respect_to(self):
         return self.page.sections.all()
 
     def get_absolute_url(self):
-        return self.page.get_absolute_url() + '#' + slugify(self.title)
+        return self.page.get_absolute_url() + "#" + slugify(self.title)
 
     def __str__(self):
         if not self.pk:
-            return str(_('New section'))
+            return str(_("New section"))
         elif not self.title:
-            return str(_('Untitled'))
+            return str(_("Untitled"))
         else:
             return self.title
 
     class Meta:
         abstract = True
-        verbose_name = _('section')
-        verbose_name_plural = _('sections')
-        ordering = ['number']
+        verbose_name = _("section")
+        verbose_name_plural = _("sections")
+        ordering = ["number"]